veranda/Parser.py

   1 #!/usr/bin/python
   2
   3 #------------------------------------------------------------------------------
   4 #                                  Veranda
   5 #                                  *Parser
   6 #                                 *Iterator
   7 #                              ~--------------~
   8 #
   9 # Original Author: Andrei "Garoth" Thorp <garoth@gmail.com>
  10 #
  11 # Description: This module takes in python-formatted DBus-SQL message and
  12 #              wraps it in an object for easy usage. One of the aims is for
  13 #              this then to be easily usable with gtk's TreeView table
  14 #              system.
  15 #
  16 # Notes:
  17 #   Indentation: I use tabs only, 4 spaces per tab.
  18 #------------------------------------------------------------------------------
  19 import time
  20 import sys
  21 #------------------------------------------------------------------------------
  22 class Parser:
  23 #------------------------------------------------------------------------------
  24         """ An abstraction layer for DBus-SQL messages. This module makes it easy
  25         to extract data from messages that Versaplex replies with over dbus."""
  26         #---------------------------
  27         def __init__(self, message):
  28         #---------------------------
  29                 """Constructor: get the message, control the workflow"""
  30                 self.message = message          # The original message
  31                 self.types = []                         # The types of each column
  32                 self.titles = []                        # The titles of each column
  33                 self.table = []                         # The table     (columns/rows for data)
  34
  35                 self.__parseColumnTypes__()
  36                 self.__parseColumnTitles__()
  37                 self.__parseTableRows__()
  38
  39         #------------------------------
  40         def __parseColumnTypes__(self):
  41         #------------------------------
  42                 """Puts in as many strings into a list as there are columns"""
  43                 segmentZero = self.message[0]
  44
  45                 for struct in segmentZero:
  46                         self.types.append(str(struct[2]))
  47
  48         #-------------------------------
  49         def __parseColumnTitles__(self):
  50         #-------------------------------
  51                 """Extracts the names of the columns from self.message and puts them
  52                 in as the first row of self.table"""
  53                 segmentZero = self.message[0]
  54                 for struct in segmentZero:
  55                         self.titles.append(str(struct[1]))
  56
  57         #----------------------------
  58         def __parseTableRows__(self):
  59         #----------------------------
  60                 """Extracts the table rows from self.message and puts them into
  61                 self.table"""
  62                 # NOTE: this will make a table of _rows_. Sometimes, there will be
  63                 #       only one element in the row (see sidebar). However, this
  64                 #       is the correct behavior. Do not "fix" it.
  65
  66                 # Fill the table
  67                 segmentOne = self.message[1]
  68                 for struct in segmentOne:
  69                         row = []
  70                         for x in range(self.numColumns()):
  71                                 colType = self.types[x]
  72                                 if colType == "DateTime":
  73                                         # If it's a tuple, try to convert to time format
  74                                         row.append(str(time.strftime("%Y/%m/%d %H:%M:%S",
  75                                                                         time.localtime(struct[x][0]))))
  76                                 else:
  77                                         row.append(str(struct[x]))
  78                         self.table.append(row)
  79
  80                 # Remove any nulls by comparing against another table
  81                 segmentTwo = self.message[2]
  82                 y = 0
  83                 for struct in segmentTwo:
  84                         row = []
  85                         for x in range(self.numColumns()):
  86                                 if struct[x]:
  87                                         self.table[y][x] = ""
  88                         y += 1
  89
  90         #--------------------
  91         def numColumns(self):
  92         #--------------------
  93                 """Returns the number of columns in the data"""
  94                 return len(self.types)
  95
  96         #-----------------
  97         def numRows(self):
  98         #-----------------
  99                 """Returns the number of rows of data (not the title row)"""
 100                 return len(self.table)
 101
 102         #----------------------------
 103         def getOriginalMessage(self):
 104         #----------------------------
 105                 """Returns the original dbus message"""
 106                 return self.message
 107
 108         #-------------------------
 109         def getColumnTitles(self):
 110         #-------------------------
 111                 """Returns a list of the titles of the columns"""
 112                 return self.titles
 113
 114         #------------------------
 115         def getColumnTypes(self):
 116         #------------------------
 117                 """Returns the types of the columns (returns a list of types, like
 118                 "str" or "int")"""
 119                 return self.types
 120
 121         #---------------------------------
 122         def getColumnTypesAsStrings(self):
 123         #---------------------------------
 124                 """Returns the same amount of strings as there are types in the
 125                 self.types list. This is useful for displaying data in a table
 126                 with gtk.ListStore."""
 127                 builder = []
 128                 for type in self.types:
 129                         builder.append(str)
 130                 return builder
 131
 132         #------------------
 133         def getTable(self):
 134         #------------------
 135                 """Returns the body of the table"""
 136                 return self.table
 137
 138         #--------------------------
 139         def getTableIterator(self):
 140         #--------------------------
 141                 """Returns a simple iterator for self.table"""
 142                 return Iterator(self.table)
 143
 144 #------------------------------------------------------------------------------
 145 class Iterator:
 146 #------------------------------------------------------------------------------
 147         """A simple iterator made for returning one table row at a time"""
 148         #-------------------------
 149         def __init__(self, table):
 150         #-------------------------
 151                 """Starts up the instance variables"""
 152                 self.table = table              # The data
 153                 self.currentRow = -1    # The location of the iterator by row number
 154
 155         #----------------------------
 156         def setCurrent(self, number):
 157         #----------------------------
 158                 """Lets you set the row that the iterator is currently on. Remember,
 159                 though that getNext() will return the next element, not the current"""
 160                 self.currentRow = number
 161
 162         #-----------------
 163         def getNext(self):
 164         #-----------------
 165                 """Returns the next row in the table"""
 166                 if self.hasNext():
 167                         self.currentRow += 1
 168                         return self.table[self.currentRow]
 169                 else:
 170                         raise IndexError, "Data table from Dbus has no next row"
 171
 172         #-----------------
 173         def hasNext(self):
 174         #-----------------
 175                 """Checks if there is a next row in the table"""
 176                 if self.currentRow+1 <= len(self.table)-1:
 177                         return True
 178                 else:
 179                         return False
 180